The cornea is a transparent, dome-shaped outermost layer of the eye. The cornea covers, the iris and the pupil and plays a role in protecting the eye from germs, dust, and other harmful matter. The cornea additionally functions to focus vision, typically contributing to more than 50 percent of the eye's total focusing power. Light that passes through the cornea is refracted onto the lens of the eye and further focused by the lens onto the retina. Thus, a healthy cornea is typically clear and transparent to allow passing of light there through. Corneal opacities can cause vision impairment and blindness.
U.S. Pat. No. 7,736,390 to Aharoni describes an artificial vision system including a sealed capsule adapted for intraocular placement upstream of a retina, an electronic display located within the sealed capsule and focusing optics located within the sealed capsule and arranged for focusing an image on the electronic display onto the retina.
U.S. Pat. No. 5,653,751 to Samiy describes apparatus and methods that project images onto the retina of an eye. The apparatus can include an image memory element for storing an image signal representative of a visual image, a projection element in an electrical circuit with the image memory element for generating an optical image signal of the type suitable for detection by a retina and being representative of the visual image, and a focus element that is adapted for implantation into the eye at a position in the eye which is posterior to the cornea and anterior to the retina and that is optically coupled to the projection element for focusing the optical image onto the retina. The projection element can include a display device that is dimensionally adapted for disposition within the eye at a position posterior to the cornea. The display device can be a liquid crystal display element that has an illuminator element optically coupled to the display device or alternatively can include a laser diode element that optically couples to a scanning mirror that projects light through a damaged cornea.